This question comes up a lot.  I think it’s important to understand the primary features and functions of what each does.

Portals arrived in the the late 1990’s with Yahoo.com and Excite.com.  They are a way of personalizing and aggregating information from disparate sources into a dashboard you can view instantly.  You can see your local weather, your sports scores, local news and view your last three emails in one glance in a look and feel you choose.

Content management grew out of a need for what is called “library services”.  Your business may have ten thousand, one hundred thousand, a million or even more documents.  But where are they stored?  Are there multiple versions of them?  What is the history of those changes?

Let’s answer the question.  “Do I need a portal or a content manager?”  Like the weather, it depends.  Portals provide some content management features.  Version control.  Search.  Workflow.  But let’s consider a few situations.

1. You have a base of more than one million records.  Browsing through a few dozen or thousand records in a user interface is fine.  Once you get over one million records, you will want robust content management tools to help.

2. You have large ingestion on a regular basis (daily, weekly, monthly)  If you have RSS feeds coming into your system nightly with specific subject matter, you will get a lot of organizational help from a content manager.

3. You need automatic categorization and routing of content on ingestion.  If you need to route incoming leads with marketing or sales keywords to your sales team and technical whitepapers to land in your engineer’s inbox, content managers can make that easy.

4. You have content-driven workflows.  Portals have some workflow definition and roles.  But if you have several dozen workflow definitions with more than ten states based on a document’s contents, you might want a dedicated way to manage it.

5. You need content modelling.  Dealing with one thousand documents is one thing.  But when you need to make three million documents available to users to search or to browse by title, keywords or custom derived fields, you will want a tool with a content model.

All this said, with products like Liferay, the boundary line between a portal and a content manager is blurring rapidly!